KR101911556B1 - Method for forming an ink jet printhead, ink jet printhead and printer - Google Patents

Abstract

A method for forming an inkjet printhead of the present invention includes providing a diaphragm including a plurality of apertures through the diaphragm; Attaching a piezoelectric array including a plurality of piezoelectric actuators to the diaphragm; Attaching a prefabricated membrane spacer to the diaphragm at locations between adjacent piezoelectric actuators, wherein the prefabricated membrane spacer is preformed prior to attachment to the diaphragm, comprises a polymer layer, and comprises a plurality of Directly to the diaphragm, the spacer not overlapping directly on the piezoelectric actuators of the diaphragm; And electrically coupling the electrical interconnection to the plurality of piezoelectric actuators, wherein the membrane spacer and the plurality of piezoelectric actuators are disposed between the diaphragm and the electrical interconnection, And electrically coupling the piezoelectric actuators to the piezoelectric actuators, wherein the inkjet printhead of the present invention further comprises: a diaphragm including a plurality of apertures through the diaphragm; A piezoelectric actuator array attached to the diaphragm; A prefabricated membrane spacer attached to the diaphragm at locations between adjacent piezoelectric actuators, the prefabricated membrane spacer comprising a polymer layer, the prefabricated membrane spacer comprising a layer of polymer, A formed film spacer; And an electrical interconnection electrically coupled to the plurality of actuators, wherein the membrane spacers and the plurality of piezoelectric actuators are interposed directly between the diaphragm and the electrical interconnect, and the printer of the present invention further comprises an ink- And a housing for receiving the inkjet printhead.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for forming an ink-jet printhead, an ink-jet printhead,

Drop-on-demand inkjet technology is widely used in the printing industry. Printers using drop-on-demand inkjet technology can use thermal inkjet technology or piezo technology. Piezoelectric inkjets are generally more popular because they are more expensive to manufacture than thermal inkjets but can use a wider range of inks and eliminate kogation problems.

Piezoelectric inkjet printheads typically include a flexible diaphragm and a piezoelectric element attached to the diaphragm. When a voltage is applied to the piezoelectric element, typically through an electrical connection with an electrode electrically coupled to a voltage source, the piezoelectric element is deflected to cause the diaphragm to bend toward the nozzle (aperture or jet) And discharges a large amount of ink from the chamber through the nozzle. When the diaphragm returns to the relaxed state, the diaphragm is bent and spaced from the nozzle, which reduces the pressure in the chamber and sucks ink from the main ink reservoir through the opening into the chamber to replace the ejected ink.

Increasing the print resolution of inkjet printers using piezoelectric inkjet technology is the goal of design engineers. Increasing the jet density of the piezoelectric inkjet printhead can increase the print resolution. One way to increase the jet density is to remove the manifold inside the jet stack. For this design, it is desirable to have a single port through the back of the jet stack for each jet. This port acts as a passage for transferring the ink from the reservoir to each ink-jet chamber. Due to the plurality of jets in the high density printhead, a plurality of ports, one for each jet, must pass vertically through the diaphragm between the piezoelectric elements.

The manufacture of high density inkjet printheads with external manifolds required new processing methods. A lesser number of equipment, fewer processing steps, and a method of manufacturing a printhead using a reduced material and a printhead manufactured by this method are preferred.

In one embodiment of the present inventive concept, a method for forming an inkjet printhead assembly includes providing a diaphragm including a plurality of apertures through a diaphragm, positioning a piezoelectric array including a plurality of piezoelectric actuators on the diaphragm Attaching a prefabricated film spacer at locations between adjacent piezoelectric actuators to the diaphragm, wherein the prefabricated membrane spacer is preformed prior to attachment to the diaphragm, Polymer layer, and attaching the spacer directly to the diaphragm, not directly superimposed on the plurality of piezoelectric actuators. The method further includes electrically coupling an electrical interconnect to the plurality of piezoelectric actuators, wherein the membrane spacer and the plurality of piezoelectric actuators are interposed directly between the diaphragm and the electrical interconnect.

In another embodiment, an inkjet printhead includes a diaphragm including a plurality of apertures passing through the diaphragm, a piezoelectric actuator array attached to the diaphragm, a pre-formed membrane spacer attached to the diaphragm at locations between adjacent piezoelectric actuators, Wherein the previously formed film spacer comprises a polymer layer and may comprise the previously formed film spacer not directly superimposed on the plurality of actuators. The inkjet printhead further comprises an electrical interconnect that is electrically coupled to the plurality of actuators, wherein the membrane spacer and the plurality of piezoelectric actuators are interposed directly between the diaphragm and the electrical interconnect.

In another embodiment, the printer may comprise an inkjet printhead, the inkjet printhead including a diaphragm including a plurality of apertures through the diaphragm, a piezoelectric actuator array attached to the diaphragm, a position between adjacent piezoelectric actuators, Wherein the prefabricated membrane spacer comprises a polymer layer and is not directly superimposed on the plurality of actuators, and the preformed membrane spacer attached to the diaphragm in the plurality of An electrical interconnection electrically coupled to the actuators, wherein the membrane spacer and the plurality of piezoelectric actuators include the electrical interconnection directly interposed between the diaphragm and the electrical interconnection. The printer may further include a housing for receiving the inkjet printhead.

Figs. 1 to 6 are cross-sectional views showing the inter-process structure of a part of an ink-jet printhead which can be formed using an embodiment of the present invention; Fig.
FIG. 7 is a cross-sectional view showing the inter-process structure of a part of an ink-jet printhead that can be formed using another embodiment of the present invention; FIG.
Figure 8 is a perspective view of a printer that may include a printhead according to the teachings of the present invention; And
Figs. 9 and 10 are cross-sectional views showing an intermediate process structure according to one embodiment. Fig.

It should be noted that certain details of the drawings have been simplified and are intended to facilitate an understanding of the concepts of the present invention rather than maintaining rigorous structural accuracy, detail, and scale. Unless otherwise specified, the term "printer" as used herein includes any device that performs printout functions for any purpose, such as a digital copier, bookbinder, facsimile machine, multifunction printer, plotter, do. The term "polymer" includes any one of a wide variety of carbon-based compounds formed from long chain molecules comprising thermosetting resins, thermoplastic resins, resins such as epoxies, polycarbonates, and related compounds known in the art .

Figure 9 illustrates one PZT inter-printhead structure 800 that may be used during the formation of an ink-jet printhead. 9 may include one partial and two complete piezoelectric actuators 802 (i.e., actuators, transducers, piezoelectric elements, or piezoelectric transducers) on a patterned stainless steel diaphragm 804, a stainless steel body plate 806, a continuous diaphragm adhesive 808 for attaching the diaphragm 804 to the body plate 806, and a stainless steel inlet / outlet plate 810. After the transducer 802 is attached to the diaphragm 804, a dielectric interstitial material, such as a liquid or paste polymer, is dispensed onto the structure to provide a dielectric intervening layer 812 as shown. During this step of the process, the diaphragm adhesive 808 is applied to cover the apertures extending through the diaphragm 804 so that the interstitial material does not flow through the openings during application of the fluid polymer intercalation material during formation of the interposition layer 812 do. The degassing process of the interstitial layer 812 may be performed in a degassing chamber and the interstitial layer 812 may be planarized using a flat plane and a heated press and then cured at elevated temperature in an oven .

Next, a process for exposing the upper surface of the actuator 802 may be performed. In this process, a patterned mask 814, such as a photoresist layer having openings 816 through the photoresist layer that exposes the piezoelectric actuator 802, is patterned using, for example, a photolithographic process, As shown in FIG. The structure of FIG. 9 may include other elements such as an adhesive layer not shown for simplicity.

9 is then etched in exposed chambers 816, e.g., using plasma etch, in an etch chamber to expose the top surface of each piezoelectric actuator 802, and the next The patterned mask 814 is removed. Etching the interposition layer 812 cleanly from the top surface of the piezoelectric actuator is a challenge, but is essential for sufficient electrical connection to the piezoelectric element 802. [ Next, an additional process may be completed on the structure of FIG. 9 to form the structure of FIG. For example, a patterned standoff layer 900 is applied to the intervening layer 812 such that the top surfaces of the transducer 802 are exposed, and a conductor 902 is applied to the top surface of the transducer 802. The standoff layer 900 includes a flow of a conductor 902 that traverses an actuator 802 to prevent a short circuit to an adjacent actuator 802. [ A printed circuit board 904 having a plurality of conductive pads 906 can be attached to the top surface of the structure such that a plurality of conductive pads 906 are electrically coupled to the piezoelectric actuator 802 through the conductors 902 have. Next, the conductor 902 can be cured using a suitable curing process.

Next, a laser ablation process is applied to the diaphragm 808, the intervening layer 812, and the diaphragm 806 to provide a plurality of ink ports 908 for the flow of ink through the openings in the diaphragm 804, May be performed from the bottom side of the structure of Figure 10 to remove material including the standoff layer 900 that covers the openings in the diaphragm 804. These ink ports 908 can be formed from a bottom side of the structure shown in Fig. 9 by using a laser to melt the diaphragm attachment adhesive 808, the interposition layer 812, and the standoff layer 900.

In the first laserfusing process, openings through the inlet / outlet plate 810, the body plate 806, and / or the diaphragm 804 itself may be used as masks to form ink ports 908 that are self-aligned during etching . This embodiment can use a laser beam that is wider than the width of the opening through the diaphragm 804 so that the laser beam is transmitted through one or more of the inlet / outlet plate 810, the body plate 806, and the diaphragm 804, Lt; / RTI > In this laserfusing process, the diaphragm 804 may be exposed during the laserfusing process such that the ink contacts the diaphragm 804 as the ink flows through the ink ports 908 during use of the printhead.

In the second laserfusing process, contact of one or more structures 810, 806, 804 is undesirable. In this process, the laser beam can pass through the mask and the beam can be shrunk to a smaller diameter than the diameter of the opening in the diaphragm 804. This laser beam can be directed through the aperture of the diaphragm such that only structures 808, 812, 900 are contacted by the laser. In this embodiment, the laser first contacts the diaphragm attachment adhesive 808, and then contacts the interposition layer 812, followed by the standoff layer 900. In this embodiment, the sidewalls of the ink port opening 908 may include a diaphragm attachment adhesive 808, an intervening layer 812, and a standoff layer 900, The steel sidewalls or other portions of the stainless steel diaphragm 804 are not exposed by the ink port 908 and the ink does not contact the diaphragm 804 as it flows through the ink ports 908 during use of the printhead .

After forming the ink port opening 908, the inter-printhead structure 910 of FIG. 10 is completed.

Higher productivity can be achieved by reducing the complexity of the manufacturing process. Moreover, lower cost products can be obtained by processes that use fewer manufacturing facilities, require less material, and reduce manufacturing time. For example, the process used to form the structure of FIG. 10 may include the use of a polymer degassing step in a degassing chamber to degas the intervening material layer to remove entrained air, the use of a heated A planarizing step using a flat plate in the press, curing of the polymer in the curing oven to cure the liquid or paste intervening material layer into a solid intervening layer, etching to remove the solid intervening layer to expose the piezoelectric actuator A plasma etch process in the chamber. In some printhead designs and processes, these tools and materials may be required. SUMMARY OF THE INVENTION An embodiment of the present invention relates to a method for forming an inkjet printhead, an inkjet printhead formed according to the method, a method for forming a printer comprising the formation of the inkjet printhead, And a printer. This process may include the use of a reduced tool set, a simplified manufacturing process, and a reduced number of structural components required to form the printhead.

1 is a cross-sectional view illustrating an inter-process structure 100 that may be formed in accordance with one embodiment of the teachings of the present invention. This embodiment illustrates a plurality of piezoelectric actuators 102 attached to a patterned diaphragm 104, such as a stainless steel diaphragm. Figure 1 further illustrates a patterned body plate 106, such as a stainless steel body plate, a diaphragm 104 and a diaphragm adhesive 108 that physically connects the plurality of actuators 102 to the body plate 106, For example, a patterned inlet / outlet plate 110, such as a stainless steel inlet / outlet plate. It will be appreciated that the illustration of the structure of Figure 1 is merely a part of the printhead assembly and that the number of piezoelectric actuators 102 as part of the piezoelectric actuator array can be hundreds or even thousands. In this embodiment, a plurality of openings 112 extend through the diaphragm 104, the diaphragm adhesive 108, the body plate 106, and the inlet / outlet plate 110. Although other embodiments are contemplated wherein the openings 112 are cleared after being covered during a subsequent laserfusing process, in this embodiment the openings 112 are formed in the diaphragm adhesive 108 (also shown in FIG. 9 by the diaphragm adhesive 808). Prior to attaching the diaphragm 104 to the body plate 106, the diaphragm adhesive 108 may be applied to the diaphragm 108 in order to form openings 112 through the diaphragm adhesive 108, A cutting die, or a mask etch in an etch process. In another embodiment, the diaphragm adhesive 108 may be an optionally applied liquid that is subsequently cured.

After forming a structure similar to that shown in FIG. 1, the membrane spacer 200 is bonded or attached to the diaphragm 104, as shown in FIG. The membrane spacer 200 may be preformed to include a plurality of ribs, and the ribs may be located between adjacent actuators, or may be located, for example, in spaces between actuators or the like. In this embodiment, the membrane spacer 200 does not overlap the actuator 102, and thus does not need to be removed from the top surface 204 of the actuator 102. [ In this embodiment, the top surface 202 of the film spacer 200 is located at an upper level of the top surface 204 of each actuator 102. In other words, the two upper surfaces 202 and 204 are not coplanar. Further, the film spacer 200 is directly interposed between the actuators 102 adjacent in the direction parallel to the upper surface of the diaphragm 104. [ In one embodiment, both the bottom surface of the actuator 102 and the membrane spacer 200 are located on the diaphragm 104. In one embodiment, the piezoelectric actuator 102 may have a thickness of about 5 microns to about 150 microns, and the film spacer 200 may have a thickness of about 5 microns to about 500 microns. The membrane spacer 200 may comprise, for example, a polyimide film, for example, Upilex® available from Ube Industries. This polyimide film can be coated on both upper and lower surfaces with an adhesive such as a thermosetting adhesive (for simplicity, shown in FIG. 6), and the backing adhesive is used to attach the polyimide film to the diaphragm 104. In another embodiment, the membrane spacer 200 comprises an adhesive, such as a thermosetting adhesive, only on the lower surface of the polymer core, which is used to attach the membrane spacer 200 to the diaphragm 104, To the diaphragm 104, as shown in FIG. In another embodiment, an adhesive is applied to the top surface of the diaphragm 104, which is used to attach both the piezoelectric transducer 102 and the membrane spacer 200 to the diaphragm 104.

In this embodiment, the membrane spacer 200 covers the opening 112 through the diaphragm 104 as shown in FIG. 2, but in other embodiments, the membrane spacer 200 can be installed with sufficient precision If present, apertures may be formed in advance through the membrane spacer (200). However, for different printhead designs, covering the openings 112 with the film spacers 200 can prevent subsequent adhesives from occluding the openings 112, as will be described below. 2, in this embodiment the membrane spacer 200 covers the opening 112 through the diaphragm 104, but the diaphragm adhesive 108 has an opening 112 through the diaphragm 104 ).

A large amount of adhesive 300 may be dispensed onto the top surface 204 of each transducer 102, as shown in FIG. 3, after forming a structure similar to that shown in FIG. In one embodiment, the adhesive 300 is a conductor, such as, for example, solder, a conductor-filled conductive paste, or a z-axis conductor. In another embodiment, the adhesive is a nonconductor (dielectric) such as an epoxy. In another embodiment described below, no adhesive is used.

Next, an electrical interconnect 400, such as a printed circuit board (PCB), a flexible circuit, or a flexible cable assembly, is attached to the structure of FIG. 3 using the adhesive 300 to form the structure of FIG. can do. The electrical interconnect 400 may include a plurality of bumps 402 and traces 404. Bump 402 may be a conductive bump, a conductive pad, or a preformed bump. In this embodiment, the membrane spacer 200 and the actuator 102 are directly interposed between the electrical interconnect 400 and the diaphragm 104 in a direction perpendicular to the top surface of the diaphragm 104, But is not directly interposed between the electrical interconnection 400 and the actuator 102. Trace 404 may transmit signals to other locations on electrical interconnect 400, for example, to provide electrical connection to a printhead driver board in accordance with known techniques. The electrical signals are transmitted from the driver board (not shown separately for simplicity) to the bumps 402 via traces 404 and then transmitted to the piezoelectric actuator 102 so that each piezoelectric actuator 102 can be individually addressed. Lt; / RTI >

In one embodiment, the adhesive 300 is conductive, and electrical coupling between each bump 402 and one of the piezoelectric actuators 102 is established through the conductive adhesive 300. In this embodiment, the conductive adhesive 300 also enables electrical communication between each piezoelectric actuator 102 and the bumps 402, as well as allowing the electrical interconnect 400 to be physically secured to the piezoelectric actuator 102 . In this embodiment using the conductive adhesive 300, since electrical communication can be established by the conductive adhesive 300, each bump 402 can physically touch one of the piezoelectric actuators 102, It may not be contacted.

In another embodiment, the adhesive 300 may be non-conductive. In this embodiment, the electrical coupling between each bump 402 and one of the piezoelectric actuators 102 can be achieved, for example, between a bump 402 and one of the piezoelectric actuators 102, Lt; / RTI > can be established through physical contact of In this embodiment, each bump 402 is in physical contact with one of the piezoelectric actuators 102. Electrical contact between each bump 402 and one of the piezoelectric actuators 102 is established through physical contact between the two structures. In this embodiment, the non-conductive adhesive 300 can physically fix the electrical interconnect 400 to the plurality of piezoelectric actuators 102. [

In another embodiment, the use of adhesive 300 between each bump 402 and one of the piezoelectric actuators 102 may be omitted. In this embodiment, each bump 402 may remain in physical contact with one of the piezoelectric actuators 102 by an adjacent mechanical bond between the electrical interconnect 400 and the membrane spacer 200. In this embodiment, the electrical contact between each bump 402 and its associated piezoelectric actuator 102 is established through physical contact between the two structures 402, 102 and the electrical interconnection to the membrane spacer 200 400 by mechanical attachment.

The openings 112 through which the ink passes during operation of the printhead may then be opened using the laser beam 500 output by the laser 502 as shown in FIG. A portion of the film spacer 200 and the flux of the electrical interconnect 400 provide a film spacer 200 similar to that shown in Figure 6 and openings 112 extending through the electrical interconnect 400, Lt; / RTI > can be obtained. In accordance with the design of the printheads, the laser 502 is positioned between the diaphragm 104 and / or the body plate 106 and the inlet / outlet apertures < RTI ID = 0.0 > The outflow plate 110 can be used as a mask. In this embodiment, openings 112 through the membrane spacer 200 and the electrical interconnect 400 are self-aligned with openings through the diaphragm. Next, the process for forming the completed printhead may continue.

The completed printhead may include various structures. For example, Figure 6 shows an aperture plate 600 having a plurality of nozzles 602, wherein the aperture plate 600 is attached to the inlet / outlet plate 110 . Figure 6 further illustrates a polymer layer 608, such as a polyimide film layer that forms at least a portion of the membrane spacer 200 of Figure 2, a first adhesive layer 610 that attaches the polymer layer 608 to the diaphragm 104 And a second adhesive layer 612 that attaches the polymer layer 608 to the interconnect layer 400. [ The first adhesive layer 610 may first be attached to either the diaphragm 104 or the polymer layer 608 and then the polymer layer 608 or diaphragm 104 may be attached to the polymer layer 608 to secure the diaphragm 104 to the polymer layer 608. [ Lt; RTI ID = 0.0 > 104 < / RTI > The first adhesive layer 610 may also be used to connect each piezoactuator 102 to the diaphragm 104.

The second adhesive layer 612 may first be attached to one of the interconnect layer 400 or the polymer layer 608 and then the polymer layer 608 to fix the electrical interconnect 400 to the polymer layer 608. [ May be attached to the other of the interconnect layer (608) or the interconnect layer (400). In another embodiment, no adhesive is formed between the electrical interconnect 400 and the film spacer 200, in which case the electrical interconnect 400 is physically attached to the piezoelectric actuators by the adhesive 300. It will be appreciated that the completed printhead may have additional structures not shown for simplicity, and that the various structures shown may be removed or modified.

7 illustrates another embodiment in which the top surface of the film spacer 650 is generally coplanar with the top surface of the piezoelectric actuators 102 (i.e., generally at the same level). The film spacers 650 can be attached to the diaphragm 104 with an adhesive 652 such that the film spacers 650 are generally flush with the piezoelectric actuators 102 as shown. Figure 7 further shows the standoff layer 654 that adheres to the upper surfaces of the film spacer 650 and the piezoelectric actuators 102. This standoff layer 654, for example, an adhesive may provide mechanical adhesion to the film spacers 650 of the electrical interconnects 400 and the piezoelectric actuators 102. This mechanical bond also allows each bump 402 to be in physical contact with one of the piezoelectric actuators 102 so that no additional conductive and mechanical attachment is needed to electrically couple the bump 402 to the piezoelectric actuators 102. [ . In this embodiment, each bump 402 has no physical contact with the conductive adhesive or the nonconductive adhesive. The trace 404 may be in physical contact with the standoff layer 612 and the standoff layer 612 may be an adhesive. The electrical coupling of the bumps 402 to the piezoelectric actuators can be established using, for example, one or more irregularities, as described above. In other embodiments, conductors or non-conductors similar to the material 300 discussed above may be used in the embodiment of FIG. 7, wherein openings in the standoff layer 654 may receive the flow of adhesive away from the bump 402 can do. In this embodiment, the standoff layer is directly superposed on the plurality of piezoelectric actuators in a direction perpendicular to the upper surface of the diaphragm, but the film spacer is not directly superposed on the plurality of piezoelectric actuators in a direction perpendicular to the upper surface of the diaphragm .

Figure 7 further illustrates that additional masks may be used to form the ink ports to form apertures 656 through the adhesive 652, the film spacers 650, the standoff layer 612, and the electrical interconnect 400 ≪ / RTI > FIG. Each opening 656 may have a diameter (in the case of a circular opening) or a width (in the case of a non-circular opening) smaller than the diameter (width) of the opening 112 passing through the diaphragm 104.

Further, the diaphragm attaching adhesive 658 may be patterned before it is attached to the diaphragm 104. In this embodiment, the width of the openings 660 through the diaphragm attachment adhesive 658 may be wider than the width of the openings 112 through the diaphragm 104. In addition, the width of the openings 112 through the diaphragm 104 is wider than the width of the openings 656 through the layers 652, 650, 654, and 400. A plurality of apertures 660 passing through the diaphragm attachment adhesive 658 are aligned with the plurality of apertures 112 through the diaphragm and are intended to be concentric with the plurality of apertures 112.

7, a mask (not shown for simplicity) having a plurality of apertures may be aligned with the printhead structure prior to attachment of the aperture plate 600, and a laser and diaphragm attachment adhesive 658 may be used, Respectively. The openings 112 in the diaphragm 104 may be used as alignment marks for alignment of the mask and printhead structure. The laser beam output by the laser can extend through the apertures in the mask, through the apertures 660 in the diaphragm attachment adhesive 658 and through the apertures 112 in the diaphragm, Lt; / RTI > In contrast to some conventional processes, the diaphragm attachment adhesive 658 does not require etching by a laser since the apertures 660 are formed in advance. For example, the liquid interstitial material is not distributed on the upper surface of the diaphragm 104, and therefore the openings 112 penetrating the diaphragm are covered to prevent the flow of the intervening material through these openings 112 Since there is no need, the openings 658 can be formed in advance. The advantage of preforming apertures 660 in the diaphragm attachment adhesive 658 is that the laser etch can not start with the diaphragm attachment adhesive 658 but can start with the adhesive 652. [ Because the laser etched openings are typically tapered, a smaller amount of material thickness is laser etched due to the previously formed layer 658. Thus, when the laser beam exits from the top surface of the structure 400 to form a laser exit opening, the diameter of the laser exit aperture on the top surface of the layer 400 is such that the diaphragm attachment adhesive 658 is in contact with the opening 112, Which is larger than when etching is required. In one embodiment, the diaphragm 104 is exposed to ink during the flow of ink through the ink ports formed by the openings 656, 112, and 660, but the laser is applied to the diaphragm 104, , The body plate (106), or the inlet / outlet plate (110).

In one embodiment, the aperture 660 through the diaphragm attachment adhesive 108 is between about 100 microns and about 250 microns, or between about 125 microns and about 225 microns, or between about 150 microns and about 200 microns, For example, it may have a width of about 175 [mu] m. The opening 112 through the diaphragm 104 may be between about 75 microns and about 225 microns, or between about 100 microns and about 200 microns, or between about 125 microns and about 175 microns, for example, about 150 microns Lt; / RTI > The adhesive 652, the film spacers 650, the standoff layer 654 and the openings 656 of the conductive interconnects 400 may be between about 25 microns and about 175 microns, or between about 50 microns and about 150 microns, Or between about 75 microns and about 125 microns, for example, about 100 microns.

In addition, apertures 656, which may be selectively formed to the desired size and smaller than the apertures 112 in the diaphragm 104, may also be used to tune the flow of ink in the printhead without redesigning the diaphragm 104 (I. E., For tuning fluid circuits). ≪ / RTI > After formation of the aperture 658, the aperture plate 600 may be attached to the inlet / outlet plate 110 using an adhesive 606.

Once the fabrication of the printhead is complete, one or more printheads according to the teachings of the present invention may be installed in the printer. Figure 8 includes ink 704 ejected from one or more of the printheads 702 and one or more of the nozzles 602 (e.g., Figures 6 and 7) in accordance with one embodiment of the present inventive concept The printer 700 shown in FIG. Each printhead 702 is configured to operate in accordance with digital instructions to produce a desired image on a print medium 706, such as a paper sheet, plastic, or the like. Each printhead 702 may reciprocate relative to the print media 706 in a scanning motion format to produce an image printed in strip form. Alternatively, the printhead 702 remains stationary and the print medium 706 is moved relative to the printhead 702, thereby producing an image of the same width as the printhead 702 in a single pass . The print head 702 may be narrower than the print medium 706, or may have the same width as the print medium 706. The hardware of the printer, including the printhead 702, can be received in the printer housing 708. [ In another embodiment, printhead 802 may be printed on an intermediate surface, such as a drum or belt (not shown for simplicity) that rotates for subsequent transfer to a print medium.

As will be understood by the disclosure of the present disclosure, a printhead according to one embodiment of the teachings of the present invention includes a polymer degassing step in a degassing chamber for degassing a liquid or paste interstitial material layer, A planarization step using a flat plate in a heated press to planarize the layer, polymer curing in a curing oven to cure the liquid or paste interstitial material into a solid intervening layer, and a solid intervening layer to expose the piezoelectric actuators Can be formed without the need for a plasma etch process in the etch chamber to remove it. Materials of the film spacers, such as polyimide membranes or other polymers, may be better compatible with the ink during use of the printhead compared to other materials such as two-part pastes that may form an intervening layer.

Further, for example, as shown in Fig. 5, the film spacer 200 is not in physical contact with the plurality of piezoelectric actuators 102. Fig. This is contrasted, for example, to the interposition layer 812 of FIG. 10 in physical contact with the plurality of piezoelectric actuators 802. Physical contact may have a buffering effect on the piezoelectric actuators 802. [ For example, a pressure pulse transmitted to the ink by the deflection of the piezoelectric actuators 102 and through the diaphragm may be reduced as a result of the contact between the intervening layer and the piezoelectric actuators 102. Thus, for example, since there is no physical contact between the membrane spacer 200 and the plurality of piezoelectric elements 102, the spikes of the pressure pulses delivered to the ink can be improved in one embodiment of the inventive idea have.

Claims (10)

1. An inkjet printhead comprising:
A diaphragm comprising: a plurality of apertures through the diaphragm, the diaphragm including a first side and a second side opposite the first side;
A piezoelectric actuator array, wherein each piezoactuator in the printhead is attached to the first side of the diaphragm, the piezoactuator array comprising:
A prefabricated membrane spacer attached to the first side of the diaphragm at locations between adjacent piezoelectric actuators, the prefabricated membrane spacer comprising a polymeric layer, wherein the prefabricated membrane spacer comprises a polymeric layer that is not directly superimposed on the plurality of actuators , The previously formed film spacer;
Wherein the membrane spacer and the plurality of piezoelectric actuators are interposed directly between the diaphragm and the electrical interconnect in a direction perpendicular to the first side of the diaphragm, The electrical interconnect; And
An aperture plate comprising a plurality of nozzles, the second side of the diaphragm being at a level interposed between the aperture plate and a respective one of the piezoelectric actuators in the printhead, Including,
Further comprising a plurality of apertures through the membrane spacer aligned with a plurality of apertures through the diaphragm providing a plurality of ink ports,
Further comprising a plurality of apertures through the membrane spacer and a plurality of apertures through the electrical interconnects aligned with a plurality of apertures through the diaphragm providing a plurality of the ink ports,
The diameter or width of each of the plurality of openings through the electrical interconnect and the diameter or width of each of the plurality of openings through the membrane spacer is less than the diameter or width of each of the plurality of openings through the diaphragm;
The diameter or width of the plurality of apertures passing through the diaphragm attachment adhesive disposed on the second side of the diaphragm is greater than the diameter or width of each of the plurality of apertures passing through the diaphragm;
The plurality of ink ports having a plurality of apertures through the diaphragm attachment adhesive, a plurality of apertures through the diaphragm, a plurality of apertures through the membrane spacer, and a plurality of apertures through the diaphragm attachment, At least in part, by at least a portion of the ink jet head. The method according to claim 1,
Wherein the membrane spacer is not directly superimposed on the plurality of piezoelectric actuators in a direction perpendicular to an upper surface of the diaphragm. delete delete delete The method according to claim 1,
The film spacer comprising a polyimide layer;
Wherein the ink-
A first layer of adhesive to attach the polyimide layer to the diaphragm and to attach a plurality of piezoelectric actuators to the diaphragm; And
And a second layer of adhesive to adhere the polyimide layer to the electrical interconnect. The method according to claim 6,
Further comprising a standoff layer attached to the upper surface of the previously formed film spacer and to the upper surface of each of the piezoelectric actuators,
Wherein the upper surface of the preformed film spacer is in a common plane with the upper surface of each of the piezoelectric actuators and the standoff layer is directly superimposed on the plurality of piezoelectric actuators in a direction perpendicular to the upper surface of the diaphragm Wherein the membrane spacer is not directly superimposed on the plurality of piezoelectric actuators in a direction perpendicular to the upper surface of the diaphragm. delete delete delete

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